#include <iostream>

#include <cstdio>

#include <cstring>

#include <cstdlib>

#include <cmath>

#include <vector>

#include <queue>

#include <map>

#include <algorithm>

#include <set>

#define MM(a) memset(a,0,sizeof(a))

typedef long long ll;

typedef unsigned long long ULL;

const double eps = 1e-12;

const int inf = 0x3f3f3f3f;

const double pi=acos(-1);

using namespace std;

struct Point{

    int x,y;

    void read()

    {

        scanf("%d%d",&x,&y);

    }

}p[105],tubao[105];

int dcmp(double a)

{

    if(fabs(a)<eps) return 0;

    else if(a>0) return 1;

    else return -1;

}

Point operator-(Point a,Point b)

{

    return (Point){a.x-b.x,a.y-b.y};

}

double dis(Point a)

{

    return sqrt(a.x*a.x+a.y*a.y);

}

double cross(Point a,Point b)

{

    return  a.x*b.y-b.x*a.y;

}

double dot(Point a,Point b)

{

    return a.x*b.x+a.y*b.y;

}

bool cmp(Point a,Point b)

{

    if(a.x!=b.x) return a.x<b.x;

    else return a.y<b.y;

}

int  convex_hull(Point *p,int n,Point *tubao)

{

    sort(p+1,p+n+1,cmp);

    int m=0;

    for(int i=1;i<=n;i++)

    {

        while(m>=2&&cross(p[i]-tubao[m-1],tubao[m]-tubao[m-1])>0) m--;

        tubao[++m]=p[i];

    }

    int k=m;

    for(int i=n-1;i>=1;i--)

    {

        while(m-k>=1&&cross(p[i]-tubao[m-1],tubao[m]-tubao[m-1])>0) m--;

        tubao[++m]=p[i];

    }

    m--;

    return m;

}

int main()

{

    int cas,n;

    scanf("%d",&cas);

    while(cas--)

    {

        scanf("%d",&n);

        for(int i=1;i<=n;i++) p[i].read();

        int k=convex_hull(p,n,tubao);

        tubao[k+1]=tubao[1];

        bool flag=true;

        double tmp=(n-2.0)*pi/n;

        for(int i=1;i<=k-1;i++)

        {

            Point a=tubao[i+1]-tubao[i],b=tubao[i+2]-tubao[i+1];

            double cosang=dot(a,b)/(dis(a)*dis(b));

            double ang=acos(cosang);

            ang=pi-ang;

            if(dcmp(ang-tmp)!=0) {flag=false;break;}

        }

        if(flag) printf("YES\n");

        else printf("NO\n");

    }

    return 0;

}